The subject disclosure relates generally to microwave attenuators, and more particularly to a cryogenic-stripline microwave attenuator device for quantum computing. Microwave attenuators are used to provide microwave signals with relatively stable power levels across a wide range of frequencies. Room temperature microwave attenuators are widely available, but such devices are not efficient from a thermal perspective. Other commercial microwave attenuators are not designed for thermalization or to reduce thermal noise, and do not have both good thermal performance and microwave performance at low temperatures.